1: With hydrogen bromide in water Heating / reflux; 2: With sodium hydroxide in water T=10°C;

1.1: water; sulfuric acid / 10 h / Reflux 1.2: 1.5 h / 0 - 30 °C 2.1: water / 70 °C / Reflux; Resolution of racemate 3.1: hydrogenchloride / water / carbon treatment 3.2: 1.5 h / 25 - 30 °C 4.1: triethylamine / methanol / 1.5 h / 10 - 20 °C 5.1: sodium tetrahydroborate; boron trifluoride diethyl etherate / tetrahydrofuran / 4 h / 0 - 50 °C 5.2: 0.17 h / 10 °C 6.1: hydrogenchloride / water; methanol / 0.75 h / 25 - 30 °C View Scheme

1.1: water; sulfuric acid / 10 h / Reflux 1.2: 1.5 h / 0 - 30 °C 2.1: water / 70 °C / Reflux; Resolution of racemate 3.1: hydrogenchloride / water / carbon treatment 3.2: 1.5 h / 25 - 30 °C 4.1: triethylamine / methanol / 1.5 h / 10 - 20 °C 5.1: sodium tetrahydroborate; boron trifluoride diethyl etherate / tetrahydrofuran / 4 h / 0 - 50 °C 5.2: 0.17 h / 10 °C View Scheme

1.1: water; sulfuric acid / 10 h / Reflux 1.2: 1.5 h / 0 - 30 °C 2.1: water / 70 °C / Reflux; Resolution of racemate 3.1: hydrogenchloride / water / carbon treatment 3.2: 1.5 h / 25 - 30 °C View Scheme

1.1: water; sulfuric acid / 10 h / Reflux 1.2: 1.5 h / 0 - 30 °C 2.1: water / 70 °C / Reflux; Resolution of racemate 3.1: hydrogenchloride / water / carbon treatment 3.2: 1.5 h / 25 - 30 °C 4.1: triethylamine / methanol / 1.5 h / 10 - 20 °C View Scheme

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